A: By crawl space I assume you mean underneath a home. If you are going to insulate under a floor and you have 16" or 24" on-centers, my insulation expert recommends using unfaced friction-fit batts with what professionals call lightning rods.

These are metal rods about the thickness of a metal coat hanger with pointed ends about two inches longer than the interior joist space. You can stick these up an unfaced batt and then install a lightning rod every 18" or so to hold up the insulation. This is a fast and easy installation.

You could also nail plywood or lattice boards to the bottom of the floor joists, but these are more expensive than lightning rods. Some people use netting, but that is a lot more work.

In some areas people call the room in the attic a crawl space. If you mean in your attic, blown insulation to a value of R-30 or greater is recommended.

To locate reputable insulation contractors to collect bids, visit Home Advisor. Fill out the appropriate service request, and be matched with the ideal service professional in your area.

by Kathy Maynard, reprinted courtesy of HomeAdvisor.com